Impact of built environment on behavioral vitality in transitional spaces: a modeling approach for university buildings in hot-humid climates

Transitional spaces in university buildings are increasingly recognized as important environments for informal learning, social interaction, adaptive climate buffering, and passive energy conservation. Their spatial performance and behavioral utilization remain insufficiently understood, particularly in hot-humid regions where passive environmental strategies are critical. This quantitative empirical study investigates how built-environment characteristics are associated with behavioral vitality in transitional spaces of university teaching buildings in a hot-humid climate. Based on field observations and in-situ environmental measurements collected from 50 transitional-space samples across five university campuses in Guangzhou, China, this study constructs a Spatial Vitality Index integrating activity density, behavioral diversity, and dwell duration. Multicollinearity among environmental variables was addressed using Principal Component Analysis (PCA), followed by regression modeling to identify dominant drivers of vitality across two building typologies: public teaching buildings and departmental teaching buildings. Results show that vitality in public teaching buildings is primarily driven by facility-landscape configuration and spatial layout, whereas vitality in departmental teaching buildings depends more on external environmental perception and overall layout. In the physical-environment dimension, illuminance is significantly positively associated with spatial vitality, whereas noise exposure is negatively associated. These findings provide both theoretical and practical evidence for improving campus social sustainability and the quality of educational environments in hot-humid regions.